June '15

For the Business of Apparel Decorating

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72 || P R I N T W E A R J U N E 2 0 1 5 niques can help with this dilem- ma. To get bright or high-strength colors, e.g., fluorescent colors, a color underbase highly improves the color strength. This process is done by creating the target color and dividing the mix so that half of the color is mixed with 10 per- cent to 25 percent high-opacity white to create an opaque second- ary plate. The remainder of the color is printed last. This print rotation would be high-opacity white, flash and cool, tinted target color, flash and cool, and full color. This process enhances the opacity while bringing the under- base color closer to the target color, making the last full-color plate easier to hit on press. COLOR FORMULATION Water-based pigments or mixing colors tend to dry quicker than conventional plastisol pigments, so store water-based components correctly with the bucket lid completely sealed to prevent evap- oration. Securing the lid immediately after using the component is the best way to assure this happens. During the addition of the components into the formula, completely mix it before printing. The unmixed pigments may result in inaccurate color or stripes and specks in the ink. Pretest all color matches before a pro- duction run to approve the color under consistent lighting. Choose the same light source that your customer will use to approve the color on his or her end. As with any color matching, keep accurate records and document any ad- ditions or changes to a formula. Create a sample print of any new color and file the strike-off with the correct formula for future color verification. For standardization, print the ink on white fabric and cure the ink com- pletely while testing a color formula- tion. This is vital to provide the most accurate color. Always check cure tem- perature in the ink film when testing for total cure. If the final color is des- ignated to print on an underbase with higher meshes, you may opt to strike accordingly and adjust the formula to perform under those conditions. If this special application is recorded, note those conditions in the formula details. Fundamentally, the pigment-base system percentage recommendations are much lower than conventional plas- tisol systems. Some percentage levels can be as low as 6 percent by weight for regular PCs and 8 percent by weight for the fluorescent PCs. Because the base is clean, these levels of pigment loading result in the desired hue and durability, but this can challenge the printer on opacity. In the circumstance that bright and highly saturated colors are required, the formulator may opt for a binder booster or cross-linking additive that allows the formula to hold an increased pigment of 8 percent to 12 percent. To mix color for directly printing on white fabrics, the color matcher may be able to cut back on the white compo- nent in the formula to achieve a more saturated or clean color. Minimizing white pigment allows for a greater window of success with on-press color adjusts. Another option is to choose a soft base for this application because it's softer for a direct-to-garment applica- tion and lowers the cost, as well. When printing on a white underbase for dark garments, the formulas could use a finished high-opacity white as COMMON ADDITIVES In some circumstances, additives can optimize results. These addi- tives change the chemistry of the inks and cannot be placed back into the original bucket, so use only when needed. • RETARDER: Under low humidity print- ing conditions, a retarder helps slow the evaporation in the screen. It can also improve the flow and prevent pigment staining in the mesh. • SATURATE: This additive helps the ink penetrate into the fabric as a wetting agent. It's suitable in towel printing or jobs that require the ink to penetrate into fabrics, such as discharge printing. • THICKENER: Only use this additive when increased viscosity is desired for a job to create a better film on the surface of the garment, resulting in better opaci- ty and complete ink film. • CROSS-LINKER: By adding a cross-linker, it helps the ink cure faster or under lower temperatures. It also improves the crock performance of the ink in the durability requirement and shortens the shelf life of the ink. Once mixed, use the ink in 12 hours. It leaves a slightly stiffer hand on the final print, and the screen open time decreases relative to the level of increased doses. • BINDER BOOSTER: When brighter col- ors are required, a binder booster allows additional percentage of pigment while securing durability requirements. • STRETCH ADDITIVE: Improve the ink elongation when required for stretch garments. It improves the crock perfor- mance for water-based inks. TABLE 1: COLOR UNDERBASE Pantone 283 C . . . . . . . . . . . . . High-Opacity White Pantone 284 C . . . . . . . . . . . . . High-Opacity White Pantone 285 C . . . . . . . . . . . . . High-Opacity White Pantone 286 C . . . . . . . . . . . . . Mixing White Pantone 287 C . . . . . . . . . . . . . Mixing White Pantone 288 C . . . . . . . . . . . . . Mixing White Pantone 289 C . . . . . . . . . . . . . Neutral Base WATER-BASED PRINTING

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